Missouri constitution
Article X: taxation
Section 4(b)

Property in the subclasses of class 1 may be defined by law, however subclasses (1),
(2), and (3) shall not be further divided, provided, land in subclass (2) may by general law
be assessed for tax purposes on its productive capability. The same percentage of value
shall be applied to all properties within any subclass. No classes or subclass shall have a
percentage of its true value in money in excess of thirty-three and one-third percent.